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Wednesday, February 26, 2014

Of Supplements, Vitamins, Placebos, and Kale

The 32 billion dollar vitamin and supplement industry has been booming during the
last decade. Financial prospects
continue to look bright, as manufacturers bank on the axiom that “prevention is
the best medicine”. However, recently
published scientific research has not been as kind to the industry as profits
were.

Herbal Supplements

Herbal supplements are usually some form of isolated plant
extract in a pill. But an October 2013 study
published by the journal BioMed Central Medicine revealed that what is inside the pill is not always the
same as what is written on the outside label.

The method of analysis used for this study is known as DNA barcoding,
which involves sequencing
a certain fraction of a genome from an unknown biological sample that is unique
for every organism. Like a UPC symbol on a
given product, a species can be identified by this small segment of its genome
once the DNA sequence is determined.

In the 2013 study, 44 different samples of herbal
supplements were tested, from 12 different manufacturers. Only 48% of the supplements tested were
proven to contain the herb that was listed on the label. Obviously, a consumer would expect their odds
of getting what they pay for to be better than the average coin toss.

Furthermore, the analysis identified plant species that were
not listed on the product label in
59% of the supplements. Finding unlisted
filler or contamination in a product is sloppy at best, and harmful at worst –
and the latter was more than just hypothetical in several cases.

Of the 12 manufacturers included in the study, only 2 were
found to be innocent of mislabeling any of their products. These study results were noted
in the New York Times, among other mainstream news outlets.

The first article was a
summarization of the results from several studies released between 2005 and
2013 that examined the health effects of vitamin supplements on older
individuals with normal diets. With
regards to cancer, cardiovascular disease, and mortality, no significant
benefit could be observed among those who took vitamin supplements. The total sample size of participants
numbered tens of thousands of people in the sum of all the studies.

The second study
included a group of 5,947 men over the age of 65, and was aimed at determining
if multivitamins boost cognitive abilities.
In standard form, the group was split, half were given a multivitamin,
and the other half was given a placebo in a double-blind
fashion. No significant difference was
noted between the two groups over the 12 year period of the study.

The third study
examined 1,708 individuals over the age of 50 who had previously suffered a
heart attack. Again the group was
divided into one half that received placebos, and one half that received a
multivitamin; administered in the standard double-blind format. No significant reduction in cardiovascular
dysfunction could be observed in the multivitamin group compared to the placebo
group over the remaining life years of the participants. This conclusion supported the findings of several earlier
studies that were reviewed in the same journal earlier in the year.

A panel of doctors and scientists including the editorial
staff of the journal made special note of these three studies in an
accompanying editorial. In summary, they stated:

“Although available evidence does not rule out small
benefits or harms or large benefits or harms in a small subgroup of the
population, we believe that the case is closed— supplementing the diet of
well-nourished adults with (most) mineral or vitamin supplements has no clear
benefit and might even be harmful. These vitamins should not be used for
chronic disease prevention. Enough is enough.”

“A daily
multivitamin/mineral supplement does not offer health benefits to healthy
Americans. Individual mineral/vitamin supplements can benefit some population
groups with known deficiencies, such as calcium and vitamin D supplements to
reduce risk of osteoporosis or iron supplements among those with deficient iron
intakes. However, in some settings, mineral/vitamin supplements have been
associated with harmful effects and should be pursued cautiously.” (A5 –
A6)

And most recently the U.S. Preventive Services Task Force (USPSTF)
published their two
cents:

“The USPSTF concludes
that the current evidence is insufficient to assess the balance of benefits and
harms of the use of single- or paired-nutrient supplements (except β-carotene
and vitamin E) for the prevention of cardiovascular disease or cancer. The USPSTF recommends against the use of
β-carotene or vitamin E supplements for the prevention of cardiovascular disease
or cancer.”
(β-carotene is metabolized in the body to form Vitamin A.)

This February 25, 2014 USPSTF report also pointed out that their recommendations are supported by independent studies
conducted by the National Institutes of Health, The Academy of Nutrition and
Dietetics, The American Cancer Society, and the The American Heart Association.

In spite of these studies, some people of course do remain unconvinced. In fact, if the great biochemist Linus Pauling were alive today, it is probable that he would be numbered among
them.

The Placebo

Although supplements that have been substituted with filler are
nothing more than placebos at best, it is possible that those who take them can
still see a benefit. This is important
to the manufacturers, because product sales are very dependent on testimonials.

In reality, the ‘placebo effect’ is not
entirely an imaginary thing. Psychology
is often a component of, or at least an influence in physiology. For instance, one study
published in the journal Science
showed decreased brain activity in regions of the brain where pain is
registered when placebos were administered to treat a controlled pain
stimulus. Follow up studies revealed a physiological
explanation: opioid
production.

In other words, the brain can be persuaded make its own
feel-good medicine with the right stimulus.
The results were surprising,
even to those conducting the studies.
The caveat is that such placebo effects cannot be sustained over a long
period of time.

Hence, the inclusion of placebos in clinical trials – the
kind that pharmaceuticals must undergo before being approved by the Food and
Drug Administration. FDA approval ensures
that products are not only effective, but also safe to a determined limit and
properly labeled. Incidentally, because
pharmaceuticals have been scientifically proven to induce a physiological
response beyond the placebo effect, they also require a prescription.

According to the Dietary Supplement Health and Education Act of 1994, products advertised as supplements do not
require this FDA approval in order to be marketed. And so although nutritional supplement manufacturers will
be held accountable if product quality is lacking in integrity, there is no
mechanism of regulation to stop them from manufacturing and marketing a
compromised product until and unless they get caught. And in the meantime, they are at liberty to
make unsubstantiated claims regarding the effectiveness of their products as long as they
add the following asterisk:

“*This statement has
not been evaluated by FDA. This product is not intended to diagnose, treat,
cure, or prevent any disease.”

Nature’s Vitamins and
Supplements

Becoming reliant on taking pills to supplement nutrients
that you assume are missing from your diet is perhaps indicative of a deeper
concern: your diet. And whether you
realize it or not, some of your diet is probably already “fortified” with
vitamins and minerals if you are eating processed foods (note the side of a box
of Lucky Charms, for instance).

Perhaps it would be prudent to skip the supplements and go straight to the foods that will give you those important
nutrients, along with natural combinations of fiber, protein, fats, and starches
in proportions that the human body has been accustomed to digesting for
thousands of years.

Since you won’t see advertisements on TV or in magazines for
carrots and spinach with superlative claims, here is a table of real data
instead. The data is taken from the USDA National Nutrient Database,
where you can find similar numbers for over 8000 other food items.

The table here shows how much of each nutrient you will find
in a 100 gram sample of the following common produce items:

Although some items may be more or less likely to be
consumed in 100 gram quantities, this is the arbitrary value I chose for the
sake of comparison because it is a realistic serving size for most items. A small banana, for instance, is about 100
grams. Among other things, you’ll note
that Kale really is highly nutritious – even if some people think that it is trendy and tastes like bug spray.

On the top is shown the U.S. Recommended Dietary Allowances for men and women of a variety of nutrients – an estimation of the average daily amount required to maintain health. It will
be obvious that man should not live on bananas alone, or any other food
item. Variety is important here. And plant life alone may not sufficiently provide
what can be more easily obtained from meats, such as iron and vitamin B12.

It is worth noting that there are also maximum recommended
amounts for some nutrients. Consider that
your body can quickly expel excess amounts of water-soluble vitamins when you
pee, but the fat-soluble vitamins are stored away in tissue for future use. And so consuming an unnatural amount of the
fat-soluble vitamins (A, D, E, and K) can lead to a toxic buildup because your
body has no quick way to clear them out.

Conclusion

Until the nutritional supplement industry is held to a higher
standard, the consumer is left with the responsibility to follow current research from legitimate sources if they want quality assurance with their product purchases. And although there is a mix of evidence
beyond the realm of pseudoscience that shows the benefits of certain
nutritional supplements, the consumer is also left with the responsibility to
sort this out on their own.